org.zkoss.zul
Class Treechildren.ExtraCtrl

java.lang.Object
  org.zkoss.zk.ui.HtmlBasedComponent.ExtraCtrl
      org.zkoss.zul.Treechildren.ExtraCtrl

All Implemented Interfaces:

Cropper, PrologAllowed

Enclosing class:

Treechildren

protected class Treechildren.ExtraCtrl
extends HtmlBasedComponent.ExtraCtrl
implements Cropper

A utility class to implement HtmlBasedComponent.getExtraCtrl(). It is used only by component developers.

Constructor Summary

protected

Treechildren.ExtraCtrl()

Method Summary

java.util.Set<? extends Component>	getAvailableAtClient() Returns a set of child components that are available at the client, or null if ALL available.
Component	getCropOwner() Returns the owner of the cropping scope.
boolean	isCropper() Returns whether it is a cropper, i.e., cropping is applied.

Methods inherited from class org.zkoss.zk.ui.HtmlBasedComponent.ExtraCtrl

setPrologContent

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Treechildren.ExtraCtrl

protected Treechildren.ExtraCtrl()

Method Detail

isCropper

public boolean isCropper()

Description copied from interface: Cropper

Returns whether it is a cropper, i.e., cropping is applied.

Note: this method is called when an child is detached, so you have to count one more for the total number of children. Example <= must be used, not <:
getChildCount() <= getPageSize()

The result of returning false is the same as not declaring with Cropper.

Specified by:

isCropper in interface Cropper

getCropOwner

public Component getCropOwner()

Description copied from interface: Cropper

Returns the owner of the cropping scope. In most cases, Cropper.getAvailableAtClient() returns only the available direct children of this compnent, and this method returns this component. It is so-called a single-level cropping, such as listbox and tree.

If you want to implement multi-level cropping, such as tree, you can consider the whole tree as a cropping scope. And, Cropper.getAvailableAtClient() returns all available items, not just the child of this component. In additions, this method returns the tree.

Specified by:

getCropOwner in interface Cropper

getAvailableAtClient

public java.util.Set<? extends Component> getAvailableAtClient()

Description copied from interface: Cropper

Returns a set of child components that are available at the client, or null if ALL available. The child components in the returned set must be in the same order of Component.getChildren(). In order words, you must use LinkedHashSet or similar to ensure the order in the returned set.

Note: for better performance, it is better to return null if all children are available at the client.

Note: the components in the returned set can have different parents. It is useful if you want to implement multi-level cropping, such as tree. Refer to Cropper.getCropOwner().

Specified by:

getAvailableAtClient in interface Cropper